I beam for a header

[Ross B]

I'm opening up a wall on the first floor of my house and it is load-bearing. There are 2x8 joists on either side of the proposed header and I would like the header to be concealed in the ceiling completly. The house is a 2 story colonial with a walk-up attic. The joists to either side of the proposed header are roughly 10' long. I'm going to support the header with steel posts all the way down to footings in the basement. My question is whether or not a standard flange I beam S 7.0 x 15.3 is sufficient. The unsupported span is 8'6". I intend to pocket the joists into the I beam and weld brackets on that will bolt to the sides of the joists. Thanks in advance for any advice. ~Ross

[mjpliv]

The 7" beam will be suffice to support the floor above but double 2x6 (triple 2x4) jack studs are fine to carry the beam if supported in the wall. If the columns are free standing in the basement use a 4 ply 2x6 to carry the load to the footings (there are going to be footings .... right?)

If you are cutting back the joists to lift the beam in place you may find it simpler to weld (continuous) a piece of 3/16" plate to the bottom of the beam so that it extends far enough past the flange to give you 1-1/2" minimum bearing for the joists. After the beam is in place with the jack studs installed you should block between the joists to stabilize the ends sitting on the extended flange.

Bolting through the ends of the joists is not a good idea because your bearing surface would realy just be the diameter of the bolts.

[mjpliv]

here is a section drawing

[mjpliv]

We try to keep everything on the forum, that way everybody benefits

Ross B wrote -

Very kind of you to answer my inquiry. Thanks again. If I were to notch the ends of the 2x8 joists to compensate for the plate thickness, could I delete the furring strips? Thanks again for the advice.
Best Regards,
~Ross

If your drywall is already applied directly to the floor joists (not recommended) then I see no real problem removing 3/16" off the bottom of the joists (the joists are only 10' long so they still work. This however is something to be very carefull doing, normally you would never notch the bottom of any structural member.)

[Ross B]

I see your point regarding notching the joists...I'll likely extend the lower flange to support the ends of the joists...I see the need for furring strips in this situation but would you recommend them for all drywall-joist scenarios?

[mjpliv]

When you fur out the bottom of the floor joists you accomplish several things.

1. - You increase the load sharing of the floor joists and they perform better.

2. - You stabilize the bottom of the floor joist helping to prevent twists.

3. - The harmonic viberations created by walking on the floor are transmitted to the outside walls better.

4. - You now have 3-1/2" of wood to attach the drywall to rather than just the 1-1/2" edge of the joists.

[Ross B]

Very compelling arguments for furring strips...I may have just changed my tactics for the rest of my ceilings...I have a very large home improvement project in progress. Regarding the S7 x 15.3 I beam, what would you estimate as my maximum unsupported span in an application similar to the one I described earlier?

[mjpliv]

My span tables jumps from 6" to 8" beams so I can't tell you for sure. The span you wanted to carry works for a 6" beam so I didn't question it. Maybe Rich has access to a steel section span table. Hey now, thats an idea! How about it Rich, online span tables for common materials?

[Rich]

Never seen anything for steel spans...
I'll make another post in the engineering section for wood span tables. I'll see if I can talk to an engineer friend of mine for a common listing of steel spans.